U.S. patent number 10,030,325 [Application Number 15/165,692] was granted by the patent office on 2018-07-24 for scrim coated products having a coextruded multi-layer coating on one side thereof.
This patent grant is currently assigned to Intertape Polymer Corp.. The grantee listed for this patent is Intertape Polymer Corp.. Invention is credited to Trevor Arthurs.
United States Patent |
10,030,325 |
Arthurs |
July 24, 2018 |
Scrim coated products having a coextruded multi-layer coating on
one side thereof
Abstract
Protective coverings are disclosed that have a scrim made up of
warp and weft members that define a plurality of interstices coated
on only a first major surface thereof by a multi-layer coating with
a first layer of the multi-layer coating juxtaposed to the first
major surface, and penetrating into the interstices of the scrim to
co-define, with the warp and weft members, an opposing second major
surface of the scrim. The first layer of the multi-layer coating
has a melting point below 100.degree. C. and comprises a copolymer
of ethylene, and provides the co-defined opposing second major
surface of the scrim with a coefficient of friction of at least 0.5
when tested with dry leather and at least 0.7 when tested with dry
rubber.
Inventors: |
Arthurs; Trevor (Truro,
CA) |
Applicant: |
Name |
City |
State |
Country |
Type |
Intertape Polymer Corp. |
Sarasota |
FL |
US |
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Assignee: |
Intertape Polymer Corp.
(Sarasota, FL)
|
Family
ID: |
57399737 |
Appl.
No.: |
15/165,692 |
Filed: |
May 26, 2016 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20160348286 A1 |
Dec 1, 2016 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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62168401 |
May 29, 2015 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
D03D
19/00 (20130101); D03D 9/00 (20130101); D03D
1/00 (20130101); D03D 15/0088 (20130101); B32B
27/12 (20130101); B32B 2270/00 (20130101); B32B
27/308 (20130101); B32B 3/30 (20130101); D10B
2321/021 (20130101); B32B 2260/046 (20130101); B32B
27/32 (20130101); B32B 2260/021 (20130101); B32B
2307/744 (20130101); B32B 2262/14 (20130101); B32B
2307/72 (20130101); B32B 5/024 (20130101); B32B
5/026 (20130101); D10B 2321/022 (20130101); B32B
27/306 (20130101); B32B 2307/71 (20130101); B32B
5/08 (20130101); B32B 2419/06 (20130101); B32B
2262/0253 (20130101); D10B 2505/20 (20130101); B32B
2307/7265 (20130101); B32B 27/08 (20130101); B32B
27/18 (20130101); B32B 27/302 (20130101); B32B
2571/00 (20130101) |
Current International
Class: |
D03D
1/00 (20060101); D03D 19/00 (20060101); D03D
15/00 (20060101); D03D 9/00 (20060101); B32B
27/12 (20060101); D04H 13/00 (20060101); B32B
27/30 (20060101); B32B 5/02 (20060101); B32B
5/08 (20060101); B32B 27/08 (20060101); B32B
27/18 (20060101); B32B 27/32 (20060101); B32B
3/30 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Other References
[NPL-1] POREX Filtration Group "Ethylene Vinyl Acetate" (Oct.
2011);
<http://www.porex.com/technologies/materials/porous-plastics/ethyl-vin-
yl-acetate/>. (Year: 2011). cited by examiner.
|
Primary Examiner: Sample; David
Assistant Examiner: Flores, Jr.; Donald M
Attorney, Agent or Firm: Placker; Jeffrey T. Holland &
Knight LLP
Parent Case Text
RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application
No. 62/168,401, filed May 29, 2015, which is incorporated herein by
reference.
Claims
What is claimed is:
1. A protective covering comprising: a scrim comprising warp and
weft members that define a plurality of interstices, the scrim
having a first major surface and an opposing second major surface;
and a multi-layer coating applied to the first major surface of the
scrim with a first layer juxtaposed to the first major surface and
a core layer on an opposed surface of the first layer relative to
the first major surface, the first layer being penetrated into the
interstices of the scrim to co-define, with the warp and weft
members, the opposing second major surface of the scrim; wherein
the first layer has a melting point below 100.degree. C., and
comprises a copolymer of ethylene; wherein the core layer comprises
polypropylene and makes up about 10% to about 90% of a total
thickness of the multi-layer coating; and wherein the co-defined
opposing second major surface of the scrim has a coefficient of
friction of at least 0.5 when tested with dry leather and at least
0.7 when tested with dry rubber.
2. The protective covering of claim 1, wherein the copolymer of
ethylene comprises, as a copolymer with the ethylene, one or more
of propylene, butane, vinyl acetate, and methylacrylate, or is a
styrene block copolymer.
3. The protective covering of claim 1, wherein the multi-layer
coating is coextruded onto the scrim.
4. The protective covering of claim 1, wherein the polypropylene is
a homopolymer of polypropylene.
5. The protective covering of claim 4, wherein the homopolymer of
polypropylene has a greater Vicat softening temperature than the
copolymer of ethylene.
6. The protective covering of claim 4, wherein the homopolymer of
polypropylene is mixed with a minor amount of low density
polyethylene.
7. The protective covering of claim 1, wherein the core layer
further comprises one or more of low density polyethylene, linear
low density polyethylene, ethyl vinyl acetate, ethylene methyl
acrylate, or copolymers of ethylene in a minor amount relative to
the amount of polypropylene in the core layer.
8. The protective covering of claim 1, wherein the multi-layer
coating has an A/B/A or A/B/C construction with a first A layer
being the first layer of the multi-layer coating.
9. The protective covering of claim 8, wherein the second A layer
or the C layer has an embossed major outermost surface.
10. The protective covering of claim 1, wherein the interstices of
the scrim define about 10% to about 40% of the surface area of the
opposing second major surface of the scrim.
11. The protective covering of claim 1, wherein the scrim is a
woven or knitted material.
12. The protective covering of claim 1, wherein the plurality of
warp and weft members each have a denier value in the range of
about 200 to about 2000 denier.
13. The protective covering of claim 1, wherein the scrim comprises
four to twelve warp members and two to eight weft members.
14. The protective covering of claim 1, wherein the protective
covering is lumber wrap or roofing underlayment.
15. The protective covering of claim 1, wherein the multi-layer
coating further comprises, in one or more layers thereof, a UV
stabilizer.
16. The protective covering of claim 1, wherein the polymer present
in the core in the greatest amount has a Vicat softening
temperature greater than that of the copolymer of ethylene.
17. The protective covering of claim 16, wherein the Vicat
softening temperature of the polymer in the core is greater than
120.degree. C., and a Vicat softening temperature of the first
layer comprising the copolymer of ethylene and a polymer of an
opposing skin layer, disposed on an opposite side of the core from
the first layer, are both less than 80.degree. C.
18. The protective covering of claim 16, wherein a melting point of
the polymer in the core is greater than 120.degree. C., and a
melting point of a polymer in a skin layer of the multi-layer
coating opposite the first layer relative to the core has a melting
point less than 100.degree. C.
19. The protective covering of claim 1, wherein the copolymer of
ethylene has a melt flow rate of about 5 g/10 min to about 50 g/10
min.
Description
TECHNICAL FIELD
The present disclosure relates to open weave or knitted scrims
having a coextruded multi-layer coating on one side thereof to
impart beneficial, selected properties thereto.
BACKGROUND
In both residential and commercial roofing applications, a roof
covering material is utilized to provide the main water protection
barrier. Whether the primary roof covering material comprises
composite shingles, metal panels or shingles, concrete or clay
tiles, wood shakes, or slate, a primary roof covering material is
used to protect the building interior from water ingress. In
addition to the roof covering material, roofing underlayment is
often used beneath the primary roof covering material. The roofing
underlayment acts as a water and moisture barrier.
It is desirable for roofing underlayment to provide a surface which
has a sufficiently high coefficient of friction ("COF") to reduce
slippage of the roofing underlayment relative to the roof and also
the bottom of shoes or boots and the top surfaces of the roofing
underlayment, in particular when an installer walks on the roofing
underlayment. The phrase "high coefficient of friction" in this
document means a sliding coefficient of friction of at least 0.5
when tested with dry leather and at least 0.7 when tested with dry
rubber (per CAN/CGSB-75.1-M88).
Roofing underlayment should be easily affixable to a roofing
surface, for example by nailing or adhesion. They should ideally be
impermeable to moisture. High tensile and tear strengths are also
desirable to reduce tearing during application and exposure to high
winds. Also, roofing underlayment should be light in weight to
facilitate ease of transport and application, and should be able to
withstand prolonged exposure to sunlight, air and water.
In another industry, lumber wrapping, a covering material that is
useable in automatic lumber wrapping machines, such as disclosed in
U.S. Pat. Nos. 7,594,375; 7,607,280; 7,836,666; and 7,997,050 is
desirable to have improved properties afforded by the scrim coated
products disclosed herein. The production of a lumber wrap from a
flat sheet requires the flat sheets to be thermally welded
together. The issue with standard, two side coated woven products
for use as lumber wrap is that the welds are stressed in peel when
the resultant welded lumber wrap is stretched over the lift of
lumber. The stresses induced to create this stretch are sufficient
to cause weld failure.
Thus, scrim coated products made from a polymer material that meets
the above-mentioned needs and, in particular, has the necessary
high COF and/or a low melting point material present on both sides
of the scrim while only applying a coating to one side of the
product are needed for these industries.
SUMMARY
Various embodiments relate to a roofing material and more
particularly to a roofing underlayment including anti-slip
properties. Other embodiments relate to an end product, lumber
wrap, suitable for use in automatic lumber wrapping machines. Both
types of products benefit from the structures disclosed herein in
that the outermost layer of the multi-layer coating is composed of
a material that is printable to be able to deliver a message or
include a company's logo and/or name, and in that the innermost
layer of the multi-layer coating is immediately adjacent a first
major surface of a scrim that has a plurality of interstices and
the innermost layer penetrates the interstices to define a portion
of the second major surface of the scrim. The innermost layer
provides a sufficiently high coefficient of friction to the second
major surface of the scrim that it is slip resistant and or has
grippable qualities for roofing and/or lumber wrap.
In one aspect, roofing underlayments are disclosed that include a
scrim defining a plurality of interstices and a multi-layer
polyolefin-based coating on one major surface of the scrim. The
multi-layer polyolefin based coating has a first layer of a
copolymer of ethylene juxtaposed to the major surface of the scrim
and penetrating the interstices thereof to define a portion of the
second major surface of the scrim, thereby imparting the second
major surface with a sufficiently high coefficient of friction. The
copolymer of ethylene may be a copolymer with propylene and/or
other monomers, butane, vinyl acetate, methylacrylate, and
combinations thereof.
A core layer between the innermost and outermost layers may be of a
material that provides improved high temperature resistance,
hydrostatic resistance, abrasion resistant, and/or toughness to the
end product. In one embodiment, the core layer includes
polypropylene.
In a lumber wrap embodiment, the two outer layers of the coating
have a lower melting point than the core layer. The lower melting
point for the outer layers allows the coating layer to be welded at
a lower temperature to the scrim, thereby reducing the loss of
strength of the scrim. The coating layer forms welded bonds through
the scrim, in particular, through the interstices in the scrim,
thereby significantly increasing the peel strength of the weld(s).
Of the two outer layers, the first layer of a copolymer of ethylene
is juxtaposed to the major surface of the scrim and penetrating the
interstices thereof to define a portion of the second major surface
of the scrim, thereby imparting the second major surface with a
sufficiently high coefficient of friction. The copolymer of
ethylene may be a copolymer with propylene and/or other monomers,
butane, vinyl acetate, methylacrylate, and combinations
thereof.
The multi-layer polyolefin-based coating includes at least three
layers including a core sandwiched between the first layer of a
copolymer of ethylene and a second layer of a copolymer of
ethylene, wherein the core is immediately adjacent to each of the
layers of copolymer of ethylene. In one embodiment, the first layer
and the second layer of copolymer of ethylene may be the same or
may be different. In one embodiment, the core includes
polypropylene, preferably a homopolymer of polypropylene. The core
may comprise about 20% to about 80% by weight of the total weight
of the multi-layer polyolefin-based coating, and the remainder of
the total weight may be split equally or unequally between the
first layer and the second layer of copolymer of ethylene. In one
embodiment, the remainder of the total weight is split as about 70%
to about 5% to the first layer, with the balance in the second
layer of copolymer of ethylene.
In one embodiment, the scrim is a woven scrim made of polyethylene,
polypropylene, copolymers thereof, and/or combinations thereof and
the interstices therein define 10% to 40% of the surface area
thereof. In another embodiment, the interstices define 15% to 25%
of the surface area of the woven scrim. The woven scrim may have a
leno weave.
In another embodiment, the scrim is a knitted scrim of polyethylene
or polypropylene, and the interstices therein define 10% to 40% of
the surface area thereof. In another embodiment, the interstices
define 15% to 25% of the surface area of the woven scrim.
BRIEF DESCRIPTION OF THE DRAWINGS
The claimed subject matter is described with reference to the
accompanying drawings. A brief description of each figure is
provided below. Elements with the same reference number in each
figure indicate identical or functionally similar elements.
Additionally, the left-most digit(s) of a reference number indicate
the drawing in which the reference number first appears.
FIG. 1 is a generalization of a coextruded coating being applied to
a scrim.
FIG. 2 is a cross-sectional, plan view of one embodiment of a scrim
coated product disclosed herein.
DETAILED DESCRIPTION
The following detailed description will illustrate the general
principles of the invention, examples of which are additionally
illustrated in the accompanying drawings. In the drawings, like
reference numbers indicate identical or functionally similar
elements.
As used herein, "sufficiently high coefficient of friction" has the
meaning set forth in the background section.
As used herein, "low density polyethylene" (LDPE) means a
polyethylene polymer that has a high degree of short and long chain
branching and a density range of 0.910 to 0.940 g/cm.sup.3.
As used herein, "linear low density polyethylene" (LLDPE) means a
polyethylene polymer that is substantially linear, with a
significant number of short branches, is commonly made by
copolymerization with short-chain olefins such as 1-butene,
1-hexene, and 1-octene, and has a density range of 0.915 to 0.925
g/cm.sup.3.
Referring to FIGS. 1 and 2, the coated scrim product, generally
designated 100 in FIG. 2, has an A/B/A or A/B/C multi-layer
polyolefin-based coating 104 coextruded onto a first major surface
114 of a scrim 102, which enables the first layer 108 of the
coating to penetrate the interstices 112 thereof and to define a
portion of the second major surface 116 of the scrim 102. That is,
the coating 104 includes two outer layers 108, 110 (A) or (A and C)
and a core layer 106 (B) therebetween, with layer 108 being
referred to herein as the first layer and layer 110 being referred
to as the second layer. In one embodiment, the outer layers are
compositionally equal and (A) comprises an ethylene copolymer. In
another embodiment, the outer layers are compositionally different
(A and C), but both comprise a copolymer of ethylene and/or
propylene. In one embodiment, the outer layers 108, 110 of
copolymer of ethylene and/or propylene may either or both include
other monomers, such as butene, vinyl acetate, methyl acrylate,
and/or additives.
Scrim
The scrim 102 may be a woven or knitted scrim having interstices
therein that define about 10% to about 40% of the surface area
thereof, measured relative to the first major surface 114 of the
scrim to which the multi-layer coating is applied. In another
embodiment, the interstices define 15% to 25% of the surface area
of the woven scrim. In one embodiment, the woven scrim is a leno
weave scrim. The scrim is made typically from polyolefin materials,
such as polyethylene, polypropylene, copolymers and other
combinations thereof, provided in the form of tapes, filaments,
and/or fibers. The tapes, filaments, and/or fibers may have a
denier value ranging from about 200 to about 2000. In one
embodiment, the scrim has from 4 to 12 tapes, filaments, and/or
fibers in the warp direction and from 2 to 8 tapes, filaments,
and/or fibers in the weft direction woven in a pattern to meet the
percentage of surface area defined by the interstices as set forth
above. In one exemplary embodiment, the scrim is made from
polypropylene material in the form of tapes having an 8.times.3
weave with four polypropylene warp pairs each tape being 0.9'' wide
and 650 denier and three weft tapes each being 0.115'' wide and
1200 denier, and having interstices defining about 20% of the
surface area of the first major surface of the scrim.
Multi-Layered Coating
The multi-layered coatings 104 of the various embodiments are
suitable for extrusion coating onto the scrim 102. Extrusion
coating of a multi-layered coating 104 onto the scrim may be
accomplished by melting the compositions for the coating in two or
more extruders and extruding through a multi-port film die onto the
scrim the layers in a desired layered arrangement, such as, but not
limited to, an A/B/A or A/B/C arrangement. The molten coextruded
layers and scrim are transported between a nip roll and a chill
roll to cool the molten compositions to create the coating. A chill
roll temperature of 45.degree. F. to 85.degree. F. is commonly
used.
The core layer (B) is or includes polypropylene, and may optionally
include one or more additives, such as the additives identified
below. In one embodiment, the polypropylene is a homopolymer. The
core layer typically accounts for about 10% to about 90% of the
total thickness of the multi-layer coating. In another embodiment,
the core layer accounts for about 20% to about 80% of the total
thickness of the multilayer coating. In yet another embodiment, the
core layer accounts for about 30% to about 70% of the total
thickness of the multi-layer coating. The total weight of the
coating can vary from about 20 g/m.sup.2 to about 150 g/m.sup.2,
and preferably about 40 g/m.sup.2 to about 100 g/m.sup.2.
The polypropylene in the core layer may be mixed or blended with
other polyolefins. In one embodiment, the polypropylene is mixed
with one or more of a low density polyethylene (LDPE), a linear low
density polyethylene (LLDPE), ethylene methyl acrylate (EMA),
ethylene vinyl acetate (EVA) or other ethylene copolymers,
preferably in a minor amount relative to the amount of
polypropylene. In this embodiment, the polypropylene is a
homopolymer of polypropylene. In one embodiment, the core layer may
include about 1% to about 20% by weight of these other polyolefins,
or more preferably about 5% to about 15% by weight thereof, or even
more preferably about 8% to about 10% by weight thereof. In one
embodiment, the core layer includes a homopolymer of polypropylene
and a minor amount of an LDPE. The core layer has a Vicat softening
point of greater than about 120.degree. C. as determined by ASTM
D1525B, ISO 1183, or the manufacturer's adopted test method that is
typically comparable thereto.
The first layer and the second layer copolymer of ethylene and/or
propylene account for the balance (about 10% to 90%) of the total
thickness of the multi-layer coating. The contribution of the first
and second layers (A) or (A and C) to the total thickness of the
film may be equal or unequal. For example, if the core accounts for
40% of the thickness of the film, then the two outer layers account
for 60% of the thickness of the film, which may be divided as 30%
of the thickness for each outer layer. Conversely, if the core
accounts for 40% of the thickness of the film, then the balance may
be divided unequally, for example as 20% of the thickness
contributed by the first layer and 40% of the thickness contributed
by the second layer or vice versa, or 10% of the thickness
contributed by the first layer and 50% of the thickness contributed
by the second layer or vice versa, etc.
The copolymer of ethylene and/or propylene may be
propylene-ethylene copolymers, an ethylene-butene copolymer, an
ethylene-vinyl acetate copolymer, an ethylene-methyl acrylate
copolymer, and combinations thereof and may include optional
additional polyethylene or polypropylene mixed therewith and/or one
or more additives, such as the additives identified below.
An ethylene copolymer that is characterized as having a high tack,
sticky nature is a good choice for the end products disclosed
herein because it will provide the second major surface of the
scrim with a higher coefficient of friction, i.e., good grip, less
slippage. Such ethylene copolymers have a melt flow rate in a range
of about 5 g/10 min to about 50 g/10 min as determined by ASTM
D1238 with 2.16 kg at 230.degree. C. or the manufacturer's adopted
test method that is typically comparable thereto, more preferably a
range of about 10 g/10 min to about 40 g/10 min, and even more
preferably a range of about 20 g/10 min to about 35 g/10 min. These
ethylene copolymers, in addition to the melt flow rate range
expressed above, have a Vicat softening temperature in a range of
about 30.degree. C. to about 110.degree. C. as determined by ASTM
D1525 or ISO 1183, or the manufacturer's adopted test method that
is typically comparable thereto, more preferably a range of about
30.degree. C. to about 90.degree. C., and even more preferably a
range of about 30.degree. C. to about 60.degree. C. Some example
copolymers that fall within the melt flow rate and the Vicat
softening temperature are available under the brands VERSIFY.TM. by
Dow Chemical Company, VISTAMAXX.TM. by ExxonMobil, and ADFLEX.RTM.
by LyondellBasell Industries Holdings B.V.
In another embodiment, the copolymer may be a styrene block
copolymer, such as styrene-ethylene-butadiene block copolymer
(SEB), styrene-ethylene-butadiene-styrene block copolymer (SEBS),
or styrene-ethylene-propylene-styrene (SEPS) block copolymer,
having a melt flow rate and a Vicat softening point within the
ranges set forth above. Examples of these polymers are available
under the brand KRATON.RTM. by Kraton Performance Polymers,
Inc.
Additives
The coatings may optionally incorporate additives in amounts up to
30% by weight in one layer, each layer, or in all the layers
combined and include, but are not limited to, antioxidants, UV
stabilizers, flame retardant agents, slip agents, antiblock
additives, printable additives, paper match additives, polar
additives, colorants, pigments, and anticorrosion additives.
Hindered phenols (e.g., IRGANOX.RTM. 1010) are useful antioxidant
additives that may be incorporated in the coatings, as are
phosphites (e.g., IRGAFOS.RTM. 168). Examples of suitable UV
stabilizers are TINUVIN.RTM. 328 and CHIMASSORB.RTM. 944. The
additives IRGANOX.RTM. 1010, IRGAFOS.RTM. 168, TINUVIN.RTM. 328,
and CHIMASSORB.RTM. 944 are all registered trademarks of, and
supplied by, BASF SE, a company of Germany. Useful flame retardant
agents are readily commercially available from A. Schulman of
Akron, Ohio, Clariant of Easton, Md., and Ampacet of Tarrytown,
N.Y. or Techmer PM of Clinton, Tenn. Examples of suitable slip
agents are erucamide and stearamide (either separately or in
combination). Suitable paper match additives are readily
commercially available from A. Schulman of Akron, Ohio.
When used, pigments and colorants may be added as part of a color
masterbatch. The color masterbatch is formed by combining the
pigments (colorant) with a polypropylene and/or polyethylene
carrier compatible with the polyolefin coatings. In general,
compatible carriers can be determined by creating extruded melt
blends and testing for phase separation in the extrudate. The color
masterbatch may be added to one or more layers in the multi-layer
coating or to all the layers in the multi-layer coating.
Embossing
The scrim coated products herein may also include an embossed
surface 120. In particular, as shown in FIG. 2, the second layer of
sticky polyolefin copolymer (i.e., the outermost layer thereof) may
be embossed with a pattern to further enhance the anti-slip
performance thereof. The method of embossing the surface imparts an
unevenness to the surface thereto, thereby increasing the roughness
of the surface, which improves wet slip resistance of the product.
There is also an improved physical grip of a shoe to the embossed
surface.
The embossing process may be part of a continuous manufacturing
process. The embossing process may involve applying heat and
pressure while running the scrim coated product through a nip
assembly, one roll of which has a positive of the pattern to be
embossed thereon. Embossment may also be undertaken on a printing
press just prior to printing the roofing underlayment. Embossment
may also be carried out by extrusion coating onto a patterned chill
roll or by direct embossment after cooling on a smooth chill
roll.
The embossment pattern may be of any type as long as it increases
the roughness of the outermost surface of the coating. For example,
and not as a limitation, in one embodiment an embossment pattern is
a sand pattern or a diamond pattern. In another embodiment, the
pattern is a small scale decorative pattern made up of interlocking
diamond shapes.
WORKING EXAMPLES
Example 1
Roofing Underlayment Product
An 8.times.3 weave of four polypropylene warp pairs of 650 denier
each, 0.09'' wide tapes and a three count weft of 1200 denier,
0.115'' wide tapes defined the woven scrim for this embodiment of a
roofing underlayment product. This woven scrim provided interstices
defining about 20% of the surface area of one major surface of the
scrim, the major surface to which a multi-layer polyolefin coating
was applied.
The coating, an A/B/A coextrusion coating, was coextruded onto one
major surface of the woven scrim. Layer A included about 1% by
weight of a UV masterbatch, about 10% by weight of a beige color
masterbatch, about 8% by weight of an antiblock masterbatch, about
10% by weight of a homopolymer of polypropylene, and about 70% by
weight of a propylene-ethylene copolymer having a melt flow rate of
25 g/10 min and a Vicat softening temperature of 33.degree. C.,
which is available from Dow Chemical as VERSIFY.TM. 4301. Layer B
included about 1% by weight of a UV masterbatch, about 10% by
weight of a beige color masterbatch, about 8% by weight of an LDPE,
and about 81% by weight of a homopolymer of polypropylene. The
Vicat softening temperature of the homopolymer of polypropylene in
the B layer is greater than the Vicat softening temperature of the
propylene-ethylene copolymer in the A layer. The Vicat softening
temperature of the homopolymer of polypropylene may be about
150.degree. C. to about 154.degree. C. with a load of about 10 N
used in the testing method.
The outermost layer (A) opposite the second surface of the scrim
was embossed to have a textured pattern. This was accomplished
using a heated, patterned roll that used pressure from a nip roll
to emboss the pattern onto the surface of the coating.
The above roofing underlayment was made in a first trial to have a
coating of 2.0 mil and in a second trial to have a coating of 3.0
mil. These two trials, having the coextruded multilayer coating
applied on only one side of the scrim, were compared against
Applicant's own commercially available two-sided anti-slip coated
scrim, roofing underlayment available under the brand name
NOVASEAL.TM. roofing underlayment.
Tables 1-4: Summary of Results of Embossed Trials compared to
NOVASEAL.TM. roofing underlayment tested with an English XL
Tribometer (Slip Tester on a scale of Slip Index from 0 to 1.0)
TABLE-US-00001 TABLE 1 Rubber Foot against embossed outer layer
opposite the second surface of the scrim WET TESTING DRY TESTING
Slip Index Value Slip Index Value Sample Identification of Failure
of Failure Trial 1 (2.0 mil) 0.6 1.0 Trial 2 (3.0 mil) 0.7 >1.0
NovaSeal AP 0.7 >1.0
TABLE-US-00002 TABLE 2 Rubber Foot against the second surface of
the scrim WET TESTING DRY TESTING Slip Index Value Slip Index Value
Sample Identification of Failure of Failure Trial 1 (2.0 mil) -
scrim side 0.6 0.9 Trial 2 (3.0 mil) - scrim side 0.5 0.9 NovaSeal
AP - back side (grey) 0.4 0.9
TABLE-US-00003 TABLE 3 Neolite Foot against embossed outer layer
opposite the second surface of the scrim WET TESTING DRY TESTING
Slip Index Value Slip Index Value Sample Identification of Failure
of Failure Trial 1 (2.0 mil) 0.6 >1.0 Trial 2 (3.0 mil) 0.7
>1.0 NovaSeal AP 0.6 >1.0
TABLE-US-00004 TABLE 4 Neolite Foot against the second surface of
the scrim WET TESTING DRY TESTING Slip Index Value Slip Index Value
Sample Identification of Failure of Failure Trial 1 (2.0 mil) -
scrim side 0.5 0.8 Trial 2 (3.0 mil) - scrim side 0.5 0.9 NovaSeal
AP - back side (grey) 0.3 0.8
The Embossed Outer Layer: As demonstrated by the comparative
analysis found in Tables 1-4, the two trial roofing underlayment
materials, Trials 1 and 2, with the coextruded, multilayer coating
applied to just one side of the scrim, performed generally, equally
well under both wet and dry testing of the embossed outer layer
against the rubber foot and the neolite foot as compared to the
NOVASEAL.TM. AP roofing underlayment.
The Second Surface of the Scrim: Importantly, the second surface of
the scrim in Trials 1 and 2, which in these two roofing
underlayment materials has the coating penetrating the interstices
of the scrim to define at least a portion of the second surface of
the scrim, showed superior results by outperforming the
NOVASEAL.TM. AP roofing underlayment under wet testing against both
the rubber foot and the neolite foot. Also, the second surface of
the scrim in Trials 1 and 2, performed generally, equally well
under dry testing against the rubber foot and the neolite foot as
compared to the NOVASEAL.TM. AP roofing underlayment.
Example 2
Lumber Wrap Product
An 8.times.3 weave of four polypropylene warp pairs of 650 denier
each, 0.09'' wide tapes and a three count weft of 1200 denier,
0.115'' wide tapes defined the woven scrim for this embodiment of a
lumber wrapping product for use in an automatic wrapping machine
such as disclosed in U.S. Pat. Nos. 7,594,375; 7,607,280;
7,836,666; and 7,997,050. This woven scrim provided interstices
defining about 20% of the surface area of one major surface of the
scrim, the major surface to which a multi-layer polyolefin coating
was applied.
The coating, an A/B/A coextrusion coating, was coextruded onto one
major surface of the woven scrim. Layer A included about 1% by
weight of a UV masterbatch, about 10% by weight of a beige color
masterbatch, about 8% by weight of an antiblock masterbatch, about
10% by weight of a homopolymer of polypropylene, and about 70% by
weight of a propylene-ethylene copolymer available from Dow
Chemical as VERSIFY.TM. 4301. Layer B included about 1% by weight
of a UV masterbatch, about 10% by weight of a beige color
masterbatch, about 8% by weight of an LDPE, and about 81% by weight
of a homopolymer of polypropylene. The melting point of the
homopolymer of polypropylene in the B layer is about 160.degree.
C., and the melting point of the propylene-ethylene copolymer in
the A layer is about 64.degree. C.
The embodiments of this invention shown in the drawings and
described above are exemplary of numerous embodiments that may be
made within the scope of the appended claims. It is contemplated
that numerous other configurations of the scrim coated products may
be created taking advantage of the disclosed approach. In short, it
is the Applicant's intention that the scope of the patent issuing
herefrom be limited only by the scope of the appended claims.
* * * * *
References